You can buy a USB wireless card(for hotspots) for your computer or use a router.
Most routers have DHCP servers which assign IP addresses to all the machines connected to them.
You can set a hostname to your computer and have it accessible via the hostname for other devices. This wouldn't require you to setup a static ip on your computer . For example if it's user@hostname, you should be able to access your webserver at http://hostname:port . If the port is 80, your server should be accessible at http://hostname to those connecting to your router.
Otherwise you can setup a static ip to your system. You can go to the network manager, go to the properties of the network, change ipv4 settings and set a valid ip address.
The valid ip address should be in the range of the router DHCP assignment.
If the router assigns an ip say, 192.168.0.104, then the ip addressess are in the range 192.168.0.0 to 192.168.0.255
You can check this using the command
ifconfig in the terminal.
Now to get the ip address of your router use the command
ip r | grep default.
Set your desired ip address in the ip address, the appropriate subnet mask and the router address for the gateway.
Once you do this the other devices would be able to connect to your machine using your preferred ip address.
Hope I've answered your question.